function loadScript(url, callback) {   
	var script = document.createElement("script");	// 设置<script>元素的内容
	script.type = "text/javascript";
	var scriptName = sessionStorage.getItem(url);	// 读取记忆
	if (!scriptName) {								// 检查是否已加载
		fetch(url)
			.then(response => response.text())
			.then(scriptContent  => {				
				script.textContent = scriptContent;			// js的内容
				sessionStorage.setItem(url, scriptContent);	// 设置记忆
				//location.reload();							// 刷新页面					
				callback(script);
				location.reload();							// 刷新页面					
			})
			.catch(error => {
				console.error('Error loading the script:', error);
			});
	}else{
		script.textContent = scriptName;	// js的内容		
		callback(script);
	}	 
}